Chlorella extract-containing product and method for improving the storage stability of the same

ABSTRACT

A  chlorella  extract-containing product of excellent safety and storage stability is provided without using a benzoate, which is a common preservative. A  chlorella  extract-containing product containing a capsicum extract at 0.020-1.63% by weight on a dry weight basis relative to a  chlorella  extract in an aqueous liquid for drinking having the  chlorella  extract as an principal ingredient. This  chlorella  extract-containing product is to be used as a  chlorella -containing beverage or a  chlorella -containing food additive. A method for improving the storage stability of a  chlorella  extract-containing product, comprising adding a capsicum extract to a  chlorella  extract at 0.020-1.63% by weight on a dry weight basis in an aqueous liquid for drinking having the  chlorella  extract as an principal ingredient.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of PCT/JP2008/064063 filed Aug. 5, 2008 and claims the benefit of priority under 35 U.S.C. §119 of Japanese Patent Application 2007-204376 filed Aug. 6, 2007 and Japanese Patent Application 2008-98686 filed Apr. 4, 2008, the entire contents of each application are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a chlorella extract-containing beverage, a chlorella extract-containing product including a food additive, and a method for improving the storage stability thereof. Specifically, the present invention relates to a chlorella extract-containing product of excellent storage stability and a method for improving the storage stability of a chlorella extract-containing product.

BACKGROUND OF THE INVENTION

Green algae of the genus Chlorella are widely distributed on the Earth, from the Frigid Zones to the Torrid Zone, and are single-cell organisms of nearly spherical form measuring 2-10 μm (micrometer) in diameter. The utility of chlorella has been mentioned variously in folklore and academic reports; representative effects thereof include animal and microbial growth promoting effects, taste corrective and deodorant effects, plant hormone effects and the like. Medically, chlorella is known to have cell activation action, growth promotion action, immune function improvement action, detoxication action, antiulcer action and the like.

Likewise, the chlorella extract obtained by being extracted from chlorella algal cells with aqueous solvent also exhibits bioactive actions. Since chlorella extract exhibits growth promotion action on bacteria, yeast, protozoans and the like, it is called chlorella growth factor (CGF). Since the strength of the growth promotion action of chlorella extract corresponds to the absorbance of chlorella extract at 260 nm, chlorella growth factor concentrations are usually expressed by absorbance OD260 value.

Because this chlorella extract has been prepared by extraction with aqueous solvent, it contains amino acids, peptides, water-soluble proteins, saccharides, water-soluble vitamins, and nucleic acid-related substances, but it does not contain chlorophyll, fibers, and water-insoluble proteins, which are present in chlorella cells.

There are a wide variety of health foods making use of these bioactivities of chlorella; in addition to chlorella processed foods in the form of tablets and the like prepared by drying and powdering chlorella cells as they are, chlorella extract-containing foods prepared from a chlorella extract solution as the raw material are available.

chlorella extract-containing beverages are disclosed in Japanese Patent Unexamined Publication Nos. HEI6-153876 and HEI7-79751, and are usually blended with chlorella extract, as well as with a sweetening agent, sour agent, antiseptic and other raw materials for beverage production and the like.

Disclosed in Japanese Patent Unexamined Publication Nos. SH049-14661, HEI6-141812, HEI10-295298, and HEM-46738 are various foods incorporating a chlorella extract-containing food additive as a food quality improver.

As stated above, a chlorella extract exhibits a wide variety of bioactivities, including growth promotion action on bacteria, yeast, protozoans and the like, so it is very rapidly perishable. For this reason, beverages containing a chlorella extract or food additives containing a chlorella extract are also perishable and are difficult to store. Furthermore, in the case of chlorella extract-containing beverages, even thermal sterilizing treatment is performed, bacteria, fungi and the like come therein after the stopper is removed, so it has been difficult to prevent the proliferation thereof.

For this reason, conventionally, chlorella extract-containing beverages have been stored, while coping with the flavor and stability issues, by combining a large number of sweetening agents and organic acids to adjust the drink to a pH of about 3, and adding a benzoate, which is a preservative in common use in beverages such as soft drinks and fruit juices.

However, benzoates have been shown to potentially produce benzene, a toxic compound known as a carcinogen, although in trace amounts, when ascorbic acid is co-present. For this reason, it is desirable that another preservative or a shelf life extender having sterilizing and antiseptic effects be used.

Meanwhile, as described in Japanese Patent Unexamined Publication No. HEI4-341169, capsicum extracts obtained by extraction with aqueous solvent are known to contain antifungal substances, and to be effective as food protecting agents. However, there is no knowledge of their influence on the quality, storability or shelf life of chlorella extracts.

SUMMARY OF THE INVENTION

As a result of continued research using a wide variety of food preservatives of natural derivation that are said to have a sterilizing or antiseptic effect, the present inventors found that capsicum extracts prevent the growth of microorganisms that proliferate in chlorella extracts without affecting the quality of the chlorella extracts.

An object of the present invention is to provide a chlorella extract-containing product of excellent safety and storage stability and a method for improving the storage stability thereof, without using a benzoate, which is a common preservative.

The chlorella extract-containing product of the present invention is characterized by the addition of a capsicum extract to a liquid having a chlorella extract as the principal ingredient thereof.

The method of the present invention for improving the storage stability of a chlorella extract-containing product comprises adding a capsicum extract to a liquid having a chlorella extract as the principal ingredient thereof.

The chlorella extract-containing product of the present invention is preferably one wherein the above-described liquid is an aqueous liquid for drinking to be used in a chlorella extract-containing beverage. Also, in the above-described method for improving the storage stability, it is preferable that the chlorella extract-containing product be an aqueous liquid for drinking. When used in a beverage, the chlorella extract-containing product of the present invention is preferably one wherein a capsicum extract is contained at 0.020% by weight or more, particularly at 0.020-1.63% by weight, relative to the chlorella extract, on a dry weight basis.

The chlorella extract-containing product of the present invention may be used as a food additive. In the above-described method for improving the storage stability, it is preferable that the chlorella extract-containing product be a food additive. This food additive can be used in a wide variety of foods; for example, the food additive can be added to cereal powders such as wheat flour in producing bread, ramen (Chinese noodles), udon (Japanese wheat noodle), cookies and the like, added to the batters of deep-fried foods, and added to miso, soy sauces, Japanese confectionery, coffee, whisky and the like.

When used as a food additive, the chlorella extract-containing product of the present invention is preferably one wherein a capsicum extract is contained at 0.065% by weight or more, particularly at 0.065-1.63% by weight, relative to the chlorella extract, on a dry weight basis.

The chlorella extract-containing product and method for improving the storage stability of the present invention have high safety and storage stability because a capsicum extract has been added to a food wherein a chlorella extract is the principal ingredient thereof. Additionally, despite the fact that an antiseptic effect is exhibited at levels similar to those with the addition of benzoate, there is no fear of benzene generation because no benzoate is contained.

When the chlorella extract-containing product of the present invention is one wherein the above-described liquid is drinking water to be used as a chlorella extract -containing beverage, and when the chlorella extract-containing product is an aqueous liquid for drinking in the method for improving the storage stability of the present invention, drinking water having high safety and storage stability is obtained. In particular, fungal growth can be suppressed even after unpacking.

When the chlorella extract-containing beverage contains a capsicum extract at 0.020% by weight or more relative to the chlorella extract, on a dry weight basis, fungal growth can be suppressed for a long time of about 1 month.

When the chlorella extract-containing product of the present invention is used as a chlorella extract-containing food additive, and when the chlorella extract-containing product is a food additive in the method for improving the storage stability of the present invention, the effect of the chlorella extract as a food quality improver is maintained, so the storage stability is excellent.

When the chlorella extract-containing food additive contains a capsicum extract at 0.065% by weight or more relative to the chlorella extract, on a dry weight basis, fungal growth can be suppressed for about 1 month.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, some modes of embodiment of the present invention are described in detail. In this specification, “%” other than “% by weight” means “% by weight”.

In a mode of embodiment of the chlorella extract-containing beverage of the present invention, a shelf life extender containing a capsicum extract is added to a chlorella extract-containing liquid adjusted to a pH of about 3 using an organic acid such as malic acid or citric acid.

The chlorella extract-containing liquid is a liquid, such as an aqueous solution, wherein a chlorella extract obtained by being extracted from chlorella algal cells with an aqueous solvent is contained as an ingredient thereof. The chlorella extract may assume any form of a chlorella extract liquid or a powder obtained by freeze-drying the same. Other forms are also acceptable.

Obtained by extraction with water solvent, the capsicum extract may assume any form of a capsicum extract liquid or a powder obtained by freeze-drying the same. Other forms are also acceptable. This capsicum extract has been shown to possess antifungal activity, and has been found to contain an ingredient effective in food protection, so it is highly effective in improving the shelf life of food.

Any chlorella extract-containing beverage wherein a capsicum extract is contained at 0.020% by weight or more relative to the chlorella extract on a dry weight basis exhibits fungicidal and antifungal effects to similar extents to those with the addition of a benzoate. In particular, it is preferable that the capsicum extract be contained at 0.020-1.63% by weight. Provided that the capsicum extract concentration in the chlorella extract-containing beverage is 10% by weight or less, the influence on the taste is small.

The shelf life extender comprises a capsicum extract and a extending agent therefor. The capsicum extract in the shelf life extender is preferably added at 3-40% by weight, more preferably at 3-30% by weight, and particularly preferably at 4-20% by weight.

Preferable extending agents include brewed vinegar and the like, which do not interfere with the effect of the capsicum extract. Brewed vinegar is preferably added at 50-90% by weight, particularly at 65-85% by weight. Other ingredients such as acetic acid, sodium acetate, glycerin fatty acid ester, and sucrose fatty acid ester, and the like may be added.

By adding this shelf life extender at 0.3-5.0% by weight, a chlorella extract beverage can be benefited by the fungicidal and antifungal effects of the capsicum extract, so as to suppress fungal growth, while the capsicum extract does not influence the taste and flavor. In particular, when the shelf life extender is added at 0.5-1.5% by weight, a beverage that constantly exhibits its effect irrespective of other additives is obtained.

Described below are specific blends for a chlorella extract-containing beverage. The chlorella extract used as the raw material is a chlorella extract liquid obtained by subjecting cleanly cultured chlorella to hot water extraction, which is a conventional method. A preferable chlorella species is Chlorella pyrenoidosa. The extract of this chlorella is preferably contained at 30-60% by weight or 30-50% by weight of the entire amount of the chlorella extract-containing liquid. By blending the chlorella extract with an optionally chosen ingredient such as a plant extract, a sweetening agent, a sour agent, a flavoring agent, a preservative and other raw materials for beverage manufacture, a chlorella extract-containing liquid is produced. Regarding the blending ratio, in particular, it is preferable to prepare an acidic liquid having a composition of fructose (or another sweetening agent) 10-25%, malic acid (or another sour agent) 0.5-1.5%, lemon essence (or another flavoring agent) 0.4-1.0%, and water 27-48%. Then, a chlorella extract beverage is produced by adding the above-described shelf life extender containing a capsicum extract to this chlorella extract-containing liquid. This chlorella extract -containing beverage wherein a capsicum extract is contained at 0.020% by weight or more relative to the chlorella extract on a dry weight basis exhibits fungicidal and antifungal effects to similar extents to those with the addition of a benzoate. In particular, it is preferable that the capsicum extract be contained at 0.020-1.63% by weight. In this chlorella extract-containing beverage, thanks to the synergistic effect of the shelf life extender, in particular the capsicum extract contained in the shelf life extender, and other ingredients contained in the chlorella extract-containing beverages, in particular fructose (or another sweetening agent) and malic acid (or another sour agent), greater antifungal effects were obtained than with the shelf life extender containing a capsicum extract used alone.

In addition to fructose, examples of the above-described sweetening agent include sucrose, oligosaccharides, glucose, high-fructose syrup, honey, glycyrrhizin, stevia, maltitol, starch syrup and the like. In addition to malic acid, examples of the sour agent include citric acid and the like. Examples of the flavoring agent include lemon flavor, citrus flavor and the like. However, these are not to be construed as limiting the scope of the invention.

By preparing a blend as described above, a chlorella extract-containing beverage having an antiseptic effect is obtained.

Next, a mode of embodiment of the food additive of the present invention wherein a capsicum extract is added to a chlorella extract is described.

The chlorella extract may assume any form of a chlorella extract liquid obtained by subjecting cleanly cultured chlorella to hot water extraction, which is a conventional method, or a powder obtained by freeze-drying the same. Other forms are also acceptable.

Prepared by extraction with water solvent, the capsicum extract may assume any form of a capsicum extract liquid or a powder obtained by freeze-drying the same. Other forms are also acceptable.

This food additive preferably contains a capsicum extract at 0.065% by weight or more relative to the chlorella extract on a dry weight basis. At these concentrations added, compared with food additives not containing the capsicum extract, a remarkable shelf life extending effect is observed. From the viewpoint of the influence on taste and the like, the capsicum extract concentration in the food additive is preferably 10% by weight or less, more preferably 1.0% by weight or less.

EXAMPLES

The present invention is hereinafter described with reference to the following Examples, to which, however, the invention is never limited.

[Process for Chlorella Extract Production]

The method used to produce a chlorella extract is as follows. First, chlorella algal cells (species Chlorella pyrenoidosa) were suspended in an aqueous solvent, and the suspension was heated to about 100° (degrees C.) with stirring, and allowed to stand for a given length of time. Subsequently, the algal cells were removed by fractionation. An aqueous solution of the extract obtained was concentrated, subjected to a deproteinization step and a sterilization step, and adjusted to a concentration such that specified bioactive ingredients were contained. In the present case, the chlorella extract was adjusted to obtain an OD260 of 400. As mentioned herein, an aqueous solution of chlorella extract having an OD260 of 400 means a chlorella extract concentration corresponding to an absorbance of 400 for an ultraviolet ray having a wavelength of 260 nm, as measured using a spectrophotometer.

[Separation and Cultivation of Fallen Bacteria in Chlorella Extract-Containing Liquid]

Containing the chlorella extract 33.0%, fructose 22.7%, malic acid 0.74%, lemon essence 0.47%, and water 43.0%, and maintained at a pH of about 3, the chlorella extract-containing liquid shown in Table 1 was prepared. The chlorella extract-containing liquid was allowed to stand in an open state indoors for 7 days, after which it was recovered, and stored at 25° (degrees C.).

Meanwhile, two kinds of fungi (fungus A and fungus B) that proliferated in the chlorella extract-containing liquid maintained at a pH of about 3 were separated and cultured on PDA medium (potato dextrose agar medium). These two kinds of fungi were added to a sterilized aseptic chlorella extract-containing liquid, and the liquid was stored for 1 month. In this case, it was fungus A only that proliferated within 1 month, so it was decided to use this fungus A in conducting a fungal growth test for 1 month after that time.

TABLE 1 Ingredients of chlorella extract-containing liquid Chlorella extract 33.03% Fructose 22.73% Malic acid 0.74% Lemon essence 0.47% Water 43.03% [Choice of Food Preservative Suitable for Chlorella Extract]

Food preservatives of natural derivation (I-XI), food preservatives (XII-XIV), and sodium benzoate (XV) were added to 10 ml of the chlorella extract-containing liquid to yield chlorella extract-containing beverages. Furthermore, a chlorella extract-containing beverage with no additive (XVI) was prepared. The ingredients and amounts added of the individual food preservatives are shown in Table 2.

TABLE 2 Amount added (% by Name of additive Number Ingredient weight) (trade mark) Manufacturer I Mustard extract 0.03 Wasaouro Emulsion Mitsubishi-Kagaku Foods Corporation II Bamboo (Phyllostachys pube) 0.3 Takex Keep Takex Labo Co., Ltd. III Milt protein (salmon-derived) 0.3 Impact-A Asama Chemical Co., Ltd. IV Capsicum extract 0.1 Ajinanba 501 Asama Chemical Co., Ltd. V Pectin degradation product 0.3 Neupectin-L Asama Chemical Co., Ltd. VI Persimmon extract 0.1 Pancil PS-SP Rilis Co., Ltd. VII Persimmon extract 0.1 Pancil BA-200-E-1 Rilis Co., Ltd. VIII Tea extract 0.1 Polyphenon 70A Mitsui Norin Co., Ltd. IX Tea extract 0.1 Polyphenon CG Mitsui Norin Co., Ltd. X Licorice oily extract 0.1 Sanlicorice-N Mitsui Norin Co., Ltd. XI Licorice oily extract 0.1 Sanlicorice-A Mitsui Norin Co., Ltd. XII ε-Polylysin 0.03 ε-Polylysin Chisso Corporation XIII Nonionic surfactants 0.01 Monoester-P Mitsubishi-Kagaku Foods Corporation XIV consisting of sucrose and 0.01 Sugar Ester P-1670 Mitsubishi-Kagaku Foods Corporation palmitic acid XV Sodium benzoate 0.04 Wako Pure Chemical Industries, Ltd. XVI No addition —

Fungus A was separated and proliferated from the above-described chlorella extract-containing liquid with fungus A cultured therein, and further cultured on PDA medium for 1 month, and a fungal liquid was prepared to obtain a fungus A concentration of 103-105/ml. This fungal liquid, 0.1 ml, was inoculated to chlorella extract-containing foods thermally sterilized at 85° (degrees C.) for 15 minutes, and the foods were stored at 25° degrees C.). Each food was macroscopically examined for the growth of fungus A after 7 days, 14 days, 21 days and 28 days of storage. The results are shown in Table 3. In the table, “+” indicates that the fungus grew, and “−” indicates that the fungus did not grow.

TABLE 3 Chlorella Presence or absence of extract- growth of fungus A Test containing After After After After microorganism beverage 7 days 14 days 21 days 28 days Fungus A I + + + + II + + + + III − + + + IV − − − + V + + + + VI Discontinued because of precipitation VII Unsuitable for drinking VIII Discontinued because of discoloration and turbidity IX Discontinued because of discoloration and turbidity X − + + + XI − + + + XII + + + + XIII − − − + XIV − − + + XV − − − − XVI + + + +

These results demonstrate that in the chlorella extract-containing beverages containing a capsicum extract (IV) or a nonionic surfactant consisting of sucrose and palmitic acid (XIII), fungal growth was suppressed until 21 days after the start of storage, although these beverages were not comparable to the chlorella extract-containing beverage containing sodium benzoate (XV). Meanwhile, because the nonionic surfactant (XIII) cannot be said to be a completely natural product, the food preservative of the capsicum extract (IV) is suitable for liquids with a chlorella extract as the principal ingredient thereof.

[Choosing Amounts of Capsicum Extract Added]

A shelf life extender containing a capsicum extract, Ajinanba 501 (“Ajinanba” is a trademark for a series of shelf life extenders manufactured by Asama Chemical Co., Ltd.; the same applies below), was added to 10 ml of a chlorella extract-containing liquid at 0.1-5.0% by weight to yield eight chlorella extract beverages in Examples; these solutions were thermally sterilized at 85° (degrees C.) for 15 minutes (see Table 5). The ingredients of Ajinanba 501 are shown in Table 4. The chlorella extract-containing liquid as it was, which did not contain the shelf life extender, was evaluated in Comparative Example 1.

TABLE 4 Table of ingredients of Ajinanba 501 Sodium acetate 20.0% Acetic acid 4.5% Capsicum water extract 4.0% Hop extract 1.0% Glycerol fatty acid ester 2.0% Sucrose fatty acid ester 1.2% Brewed vinegar 67.3%

Fungus A was separated and proliferated from the above-described chlorella extract-containing liquid with fungus A cultured therein, and further cultured on PDA medium for 1 month, and a fungal liquid was prepared to obtain a fungus A concentration of 103-105/ml; 0.1 ml of the liquid was inoculated in Examples and Comparative Example, and stored at 25° (degrees C.). Each solution was macroscopically examined for the growth of fungus A after 7 days, 14 days, 21 days and 28 days of storage. The results are shown in Table 5. In the table, “+” indicates that the fungus grew, and “−” indicates that the fungus did not grow.

TABLE 5 Dry weight ratio (% by weight) of capsicum Capsicum Presence or absence of Test Beverage extract to extract growth of fungus A micro- (% by weight of chlorella (% by After After After After Hot organism Ajinanbe 501) extract weight) 7 days 14 days 21 days 28 days taste Fungus A Example 1 (0.1%) 0.033 0.004 − − − + ◯ Example 2 (0.2%) 0.064 0.008 − − − − ◯ Example 3 (0.3%) 0.049 0.012 − − − − ◯ Example 4 (0.5%) 0.099 0.02 − − − − ◯ Example 5 (1.0%) 0.20 0.04 − − − − ◯ Example 6 (2.0%) 0.41 0.06 − − − − ◯ Example 7 (3.0%) 0.62 0.12 − − − − ◯ Example 8 (5.0%) 1.04 0.2 − − − − ◯ Comparative + + + + ◯ Example 1 (0%) (−: no fungal growth was observed; +: fungal growth was observed; ◯ (circle): no hot taste was sensed; Δ (triangle): a hot taste was sensed)

From these results, it is seen that in the chlorella extract-containing beverages containing a food preservative containing a capsicum extract (Ajinanba 501), fungal growth was suppressed. In particular, in the chlorella extract-containing beverages supplemented with the shelf life extender (Ajinanba 501) at 0.2% by weight or more, no fungal growth was observed even after 28 days passed after inoculation of the fungus. In all of Examples 1 to 8, there was no influence of the capsicum extract on the taste and flavor.

Next, embodiments of chlorella extract food additives are described below.

Test Example 1

Sixteen kinds of food additives were prepared by adding shelf life extender containing a capsicum extract (Ajinanba 301A and 501) to 10 ml of a chlorella extract (OD260=400) at 0.1-5.0% respectively. These were evaluated in Examples 9 to 24. These food additives were heated to 85° (degrees C.), and kept to stand for 15 minutes to achieve thermal sterilization. The ingredients of Ajinanba 301A are shown in Table 6. The chlorella extract not supplemented with the shelf life extender was evaluated in Comparative Example 1.

TABLE 6 Table of Ingredients of Ajinanba 301A Capsicum extract 20.0% Brewed vinegar 80.0%

A fungal liquid having a fungus A concentration of 103-105 /ml was prepared as described above. 0.1 ml of the fungal liquid was inoculated to the food additives in Examples 9 to 24 and the chlorella extract food additive in Comparative Example 2, and stored in an incubator at 25° (degrees C.). Each solution was macroscopically examined for the growth of fungus A after 7 days, 14 days, 21 days and 28 days of storage. The results are shown in Table 7. In the table, “+” indicates that fungal growth was observed, and “−” indicates that no fungal growth was observed.

TABLE 7 Dry weight ratio (% by weight) of capsicum Test Food additive (shelf-life extract to Presence or absence of micro- extender and its % by chlorella growth of fungus A organism weight) extract 7 days 14 days 21 days 28 days Fungus A Example 9 (301A, 0.1%) 0.033 + + + + Example 10 (301A, 0.3%) 0.098 − − − − Example 11 (301A, 0.5%) 0.163 − − − − Example 12 (301A, 0.7%) 0.228 − − − − Example 13 (301A, 1.0%) 0.326 − − − − Example 14 (301A, 2.0%) 0.852 − − − − Example 15 (301A, 3.0%) 0.978 − − − − Example 16 (301A, 5.0%) 1.63 − − − − Example 17 (501, 0.1%) 0.0065 + + + + Example 18 (501, 0.3%) 0.020 + + + + Example 19 (501, 0.5%) 0.033 + + + + Example 20 (501, 0.7%) 0.046 − + + + Example 21 (501, 1.0%) 0.065 − − − − Example 22 (501, 2.0%) 0.13 − − − − Example 23 (501, 3.0%) 0.20 − − − − Example 24 (501, 5.0%) 0.326 − − − − Comparative Example 2 (0%) — + + + + (+: fungal growth was observed; −: no fungal growth was observed)

From these results, it is seen that the chlorella extracts (food additives) containing a shelf life extender containing a capsicum extract (Ajinanba 301A and 501) suppressed fungal growth. In particular, in the food additives supplemented with the shelf life extender Ajinanba 301A at 0.3% or more (dry weight ratio of capsicum extract to chlorella extract 0.098% by weight), or with Ajinanba 501 at 1.0% or more (dry weight ratio of capsicum extract to chlorella extract 0.065% by weight), no fungal growth was observed even after 28 days passed after inoculation of the fungus. In all of Examples 9 to 24, there was no influence of the capsicum extract on the taste and flavor.

Test Example 2 Chlorella Extract-Containing Beverages

Next, 16 kinds of food additives were produced by adding shelf life extenders containing a capsicum extract (Ajinanba 301A and 501) to a chlorella extract to obtain final concentrations of 0.1-5.0% of each extender. Using these food additives, the chlorella extract-containing beverages configured as shown in Table 8 were prepared. These were evaluated in Examples 25 to 40. Meanwhile, a chlorella extract-containing beverage incorporating a chlorella extract not supplemented with any shelf life extender was prepared, and this was evaluated in Comparative Example 3. These were thermally sterilized by being retained at 85° (degrees C.) for 15 minutes, and tested using fungus A in the same manner as the above. The results are shown in Table 9.

TABLE 8 Food additive 34.0% Fructose 22.0% Malic acid 0.74% Lemon essence  0.47% Water 42.79%  Results of fungus A growth test of chlorella extract-containing beverages

TABLE 9 Capsicum Chlorella extract-containing extract Test beverage (shelf-life concentration Presence or absence of micro- extender and its % by (% by growth of fungus A organism weight) weight) 7 days 14 days 21 days 28 days Fungus A Example 25 (301A, 0.1%) 0.0068% − − − − Example 26 (301A, 0.3%) 0.0204% − − − − Example 27 (301A, 0.5%)  0.034% − − − − Example 28 (301A, 0.7%) 0.0476% − − − − Example 29 (301A, 1.0%)  0.068% − − − − Example 30 (301A, 2.0%)  0.136% − − − − Example 31 (301A, 3.0%)  0.204% − − − − Example 32 (301A, 5.0%)  0.34% − − − − Example 33 (501, 0.1%) 0.00136%  − − − − Example 34 (501, 0.3%) 0.0408% − − − − Example 35 (501, 0.5%) 0.0068% − − − − Example 36 (501, 0.7%) 0.00952%  − − − − Example 37 (501, 1.0%) 0.0136% − − − − Example 38 (501, 2.0%) 0.0272% − − − − Example 39 (501, 3.0%) 0.0408% − − − − Example 40 (501, 5.0%)  0.068% − − − − Comparative Example 3 (0%) — + + + + (+: fungal growth was observed; −: no fungal growth was observed)

From these results, it was seen that fungal growth was suppressed in the chlorella extract-containing beverages containing food additives supplemented with the shelf life extenders containing a capsicum extract (Ajinanba 301A and 501). Particularly, thanks to the synergistic effect of said food additives supplemented with the shelf life extenders, in particular the capsicum extract contained in the shelf life extender, and other ingredients contained in the chlorella extract-containing beverages, in particular fructose and malic acid, greater antifungal effects were obtained than with the food additives, i.e. the shelf life extenders containing a capsicum extract, used alone.

As is evident from the results in Table 7 and Table 9, the food additives prepared by adding the shelf life extenders containing a capsicum extract to the chlorella extract maintained their effects as chlorella extract quality improvers, and increased the safety and storage quality without affecting the tastes of the foods.

While specific embodiments of the invention have been described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. 

1. A method for improving the storage stability of a chlorella extract containing product consisting essentially of adding a 30-60% by weight chlorella extract, a 0.020-1.63% by weight capsicum extract and malic acid together.
 2. A method for improving the storage stability of a chlorella extract containing product consisting essentially of adding a 30-60% by weight chlorella extract, a 0.020-1.63% by weight capsicum extract and citric acid together. 